Alfred Hitchcock once joked that someone should turn Les Miserables into a musical; surprisingly, someone actually did, and a damned successful one at that.

But the artistic creation of a great novel onstage is no minor feat: The scope, the character, the themes and depth of plot can be daunting. And it’s not like the stage is the ideal venue for embodying water and animals.

So when out composer Jake Heggie told the Dallas Opera board five years ago that he wanted to adapt Moby-Dick — Herman Melville’s sweeping allegory of a whale hunt and fanaticism — to premiere at the Winspear Opera House … well, the floor of the boardroom must have been covered in dropped jaws.

Now that the opera is about to open, the capstone to a nearly year-long tumult touting the new Downtown Arts District, Heggie’s instincts can only be seen as visionary. No one has been this excited about Moby-Dick since they aced their 10th grade book report.

A lesser composer probably would not have generated such anticipation. Heggie’s first full-scale opera, 2000’s Dead Man Walking opened when he was almost 40, but practically reinvented the American opera and catapulted him to the ranks of musical royalty. There’ve been three more in the intervening decade, but nothing as ambitious as Moby-Dick.

"I never doubted that the music was there," Heggie says. "But turning a 600-page novel into a coherent libretto is a challenge. And a score this massive is complicated, with eight soloists and 70 musicians in the pit."

In short, finishing it in time for the hard open date of April 30 required an obsessiveness akin to that of Ahab himself.

Despite the size of the task, Heggie’s public face during the final stages of composition — he visited with me on several occasions over the course of 14 months — has been cheery and relaxed. He exudes both inspiration and organization: Basic scoring done — check; vocal parts distributed to soloists — check; orchestrations on track — check.

But it hasn’t always been so fluid. "Nerve-wracking" is the word Heggie freely uses, even if he doesn’t show it.

Heggie initially began working on the score with a libretto by Terrence McNally, his Dead Man Walking collaborator; when McNally’s health prevented him from continuing, Gene Scheer, who wrote Therese Raquin for the Dallas Opera a decade ago, stepped in. But the process was not without its stumbling blocks.

"I struggled a lot finding the music," Heggie explains. "My imagination is a crock-pot of everything I’ve ever heard. I was trying to compose a coherent world where these characters could live musically. I don’t write for the singers, I write for the characters, though it’s important for me to know who I’m dressing it on. I love motifs — audiences really respond to themes, as with events or characters. So [eventually] I took the path of least resistance and started with an aria by Ahab that I knew I wanted. Then things just started [working themselves out]." He finished up in six and a half months — "very fast for me, though for Mozart, not so fast."

The finished product is set entirely on the whaling ship Pequod, with a cast of all men … plus one "trouser role:" A woman who plays a man. With that much testosterone, did Heggie envision any romantic themes that, in the parlance of the day, "dare not speak their name?"

"The relationship between Queequeg and Ishmael is certainly open to interpretation, though we don’t go too far into that aspect," Heggie says.

Ishmael — called "Greenhorn" in the libretto — is found floating on Queequeg’s coffin, and Melville’s book describes a close kinship as well (they share a bed). And Heggie considers Queequeg the "spiritual center of the piece," while Greenhorn is "a lost soul, like so many people were during the 19th century and the Industrial Revolution. He’s a young man looking for meaning in his life."

To hear Heggie describe his work can sound like it’s more character study than grand opera; that would be a premature conclusion.

"There’s a lot of percussion," he says. "We definitely wanted to create a feeling for something epic."

So how about the big conundrum: How do you put a whale onstage? Heggie’s not saying.